Shear mechanism

ABSTRACT

An apparatus for cutting a moving elongated element by employing cooperative cutting blades mounted on spaced rotatable shafts. The shafts are interconnected by gear means and are driven by a reciprocally operating drive mechanism acting through a one-way clutch assembly.

United States Patent Sieurin SHEAR MECHANISM [72] Inventor: Donald Sieurin, Northboro, Mass.

[73] Assignee: Morgan Construction Company, Worcester, Mass.

[22] Filed: Aug. 6, 1970 [21] Appl. No.: 61,708

[52] U.S. Cl ..83/343, 83/591 [51] ..B26d 1/56 [58] Field of Search ..83/343, 345, 591, 674; 74/30,

[56] References Cited UNITED STATES PATENTS 2,764,238 9/1956 Rusinoff ..83/343X [451 July 18, 1972 3,410,163 11/1968 Taylor ..83/343X 3,424,043 1/1969 Martin ..83/343X Primary ExaminerAndrew R. J uhasz Assistant Examiner-David R. Melton Attorney-Chittick, Pfund, Birch, Samuels & Gauthier 571 ABSTRACT An apparatus for cutting a moving elongated element by em ploying cooperative cutting blades mounted on spaced rotatable shafts. The shafts are interconnected by gear means and are driven by a reciprocally operating drive mechanism acting through a one-way clutch assembly.

7 Clains, 5 Drawing Figures PATENTEUJuu 8I972 3,577,120

sum 1 OF 3 FIG.I

FlG.2

L iii 2 INVENTOR.

DONALD SI EURIN BY 5 4M, 5,-6.4

' ATTORNEYS PATENT Eu JUL 1 8 I972 sum 2 OF 3 .120

ID :3 Q

NK B r q I I0 O N m w o INVENTOR. Q 8 w Y DONALD SIEURIN ATTORNEYS PATENTEUJUUBM SHEET 3 [1F 3 33577120 F|G.5 DONALD SIEURIN B cLM 5424016064 W ziw ATTORNEYS SHEAR MECHANISM DESCRIPTION OF THE INVENTION This invention relates generally to shears, and more particularly to an improved rotary shear for cutting a moving elongated element. The invention is especially useful in the cutting of moving product lengths in a rolling mill, although it will be appreciated from the following detailed description that other uses are also contemplated.

In certain rolling mill installations, for example those designed to roll in line with a continuous casting process, a shear mechanism is usually positioned between the first mill stand and the continuous casting apparatus. The shear operates to crop the front end of the continuously cast section until a homogeneous section can be entered in the first mill stand. in addition, the shear also operates to divide a continuously cast section into short lengths when cobble cutting.

The various conventional shear designs which have been either employed in the past or considered to accomplish these functions have been found wanting in several respects. For example, hydraulically actuated shears of the type which traverse linearly with the stock require considerable time to re-cycle, and this in turn produces excessively long crop or cobble cuts. Electrically powered shears must of necessity employ large and expensive motors, brakes, etc. in order to develop the high torques required to shear large cross-sections. Inertial shears having cutting blades which travel at speeds greatly in excess of the stock approaching the first mill stand, with the result that an undesirable pull is exerted on the stock each time a cut is made.

One of the principal objects of the present invention is to overcome the disadvantages mentioned above without giving rise to other like problems and disadvantages.

A more particular object of the present invention is to provide a shear mechanism which operates efficiently on stock moving at relatively slow speeds, and which has the capability of rapidly recycling itself during a cobble cutting operation. Another object of the present invention is to provide a low cost shear mechanism which has the capability of developing the high torques required to cut large cross-sections.

These and other objects and advantages of the present invention will become more apparent as the description proceeds with the aid of the accompanying drawings wherein:

FIG. 1 is a side view with portions in cross-section, of the shear mechanism embodying the concepts of the present invention;

FIG. 2 is a view in front end elevation of the apparatus shown in FIG. 1;

FIGS. 3 and 4 are sectional views taken on lines 3-3 and 4-4 respectively of Fig. 1; and,

FIG. 5 is a side view of an alternate embodiment of the invention.

Referring initially to FIGS. 1 and 2, there is generally indicated at 2 a shear mechanism having a base 4 supporting an upstanding housing 6. Shafts 8a and 8b are journalled between suitable bearings 10 for rotation in the housing 6. The shafts rotate about laterally spaced parallel axes, and each shaft has one end 12 protruding laterally from one end of the housing 6. Collars 14 are keyed to the shaft ends 12, and each collar in turn has radially extending cutting blades 16 secured thereto.

The shear mechanism 2 is positioned such that the stock to be cut, for example a continuously cast section, moves along a path depicted schematically at 18. As shown in the drawings, the blades 16 are rotatably adjusted to a neutral position which allows stock to proceed uninterruptedly along path 18. The stock is cut by imparting simultaneous 90 rotation to both shafts 8a and 8b, the lower shaft 8b being rotated in a clockwise direction while the upper shaft 80 is rotated in the opposite counterclockwise rotation.

A pinion gear 200 is keyed to the upper shaft 8a. Gear 20a meshes with a second pinion gear 20b keyed to the lower shaft 8b, and both gears are preferable enclosed within the housing 6. The lower shaft 8b is further provided with an axial extension which extends laterally from the other end of the housing and which is keyed as at 22 to a collar 24, the latter forming a part of a one-way clutch assembly generally indicated at 26. The clutch assembly further includes an exterior collar made up of a ring 28 bolted as at 30 to a somewhat dish-shaped element 32, the latter having a shaft extension 34 aligned concentrically with the lower shaft 8b. As is best shown in Fig. 4, collar 24 is provided with a series of notches indicated typically at 36. The notches are adapted to receive a pawl 38 which is pivotally attached as at 40 to ring 28 for movement into and out of a suitably dimensioned recess 42. A coiled spring 44 or other like resilient member is employed to urge the pawl 38 inwardly towards the inner collar 24.

With the above-described arrangement, it will be seen that as viewed in FIG. 4, rotation of shaft extension 34, element 32 and ring 28 in a clockwise direction will result in a corresponding rotation of collar 24 and shaft 8b due to the mechanical connection provided by the pawl 38 being seated in one of the notches 36. Due to the mechanical connection provided by the meshed pinion gears 20a and 20b, the upper shaft 8a is simultaneously rotated in a counterclockwise direction, and when this occurs, the blades 16 cooperate to cut stock moving along path 18. When the shaft extension 34 is rotated in the opposite direction, the clutch assembly will wheel" with no corresponding rotation being imparted to shaft 8b.

The drive mechanism generally indicated at 46 for driving shaft extension 34 includes a housing 47 containing a pinion gear 48 keyed to shaft 34 as at 50. Gear 48 meshes with a pair of upper and lower gear racks 52a and 52b. Each gear rack is mounted within the housing 47 for axial reciprocating movement in a direction transverse to the rotational axis of shaft extension 34. The upper gear rack is provided at its opposite ends with pistons 54 contained for axial movement within cylinder extensions 56a and 56b of the housing 47. The lower rack 52b is likewise provided at opposite ends with pistons 54 contained within cylinder extensions 56c and 56d. Hydraulic lines 60 connect each of the cylinder extensions to a remote source of pressurized hydraulic fluid (not shown).

The apparatus functions as follows: when the stock moving along path 18 is to be cut, hydraulic fluid is fed into cylinder extensions 56a and 56d, causing the upper rack 52a to move to the right and the lower rack 52b to move to the left as viewed in Fig. 3. The gear racks act through pinion gear 48 to rotate shaft extension 34 in a clockwise direction as viewed in Fig. 3. As previously explained, by virtue of the one-way drive connection provided by clutch assembly 26, and the mechanical connection between shafts 8a and 812 provided by the meshed pinion gears 20a and 20b, rotation of shaft extension 34 rotates the shear blades 16 to effectuate a cut on the moving stock. The stroke of the pistons 54 within their respective cylinder extensions is such that the shaft extension 34 is rotated through approximately The speed at which the pistons 54 are advanced, coupled with the gear ratios of the various pinion gears, causes the shear blades to rotate at approximately the same speed as that of the moving stock. This avoids imparting any harmful pulling effect to the stock. By employing two gear racks 52a and 52b and their associated pistons, a high torque level is developed immediately and this enables the apparatus to operate on large cross-sections.

As soon as a cut is performed, hydraulic fluid is fed into cylinder extensions 56b and 56c while at the same time bleeding fluid from cylinder extensions 56a and 56d. This produces an immediate 90 rotation of shaft extension 34 in a counterclockwise direction as viewed in FIG. 3. However, because of the free-wheeling feature of clutch assembly 26, corresponding rotation is not imparted to the shafts 8a and 8b. In other words, the one-way clutch assembly 26 allows the drive mechanism 46 to re-cycle itself without rotating the shafts which carry the cutting blades. As soon as the drive mechanism is reset, the apparatus is ready to perform the next cut.

By way of example an apparatus as shown in FIGS. 1-4 may be employed in a rolling mill between a continuous casting apparatus and the first roll stand, where product having a crosssectional area a 4 square inches is being produced at a casting rate of approximately 40 tons per hour travels at a speed of around 25 feet per minute. The apparatus is capable of performing smooth efficient cuts on this type of stock, and of resetting itself rapidly enought to perform successive cobble cuts which produce scrap sections approximately 30 inches in length. This may be contrasted to the operation of conventional linear type hydraulic shears which normally produce scrap sections of between 6 and 7 feet in length under the same operating conditions.

FIG. illustrates an alternate embodiment of the invention wherein both the upper and lower shafts 8a and 8b are each connected through one way clutch assemblies 26' to upper and lower drive mechanisms 46a and 46b. While one drive mechanism is driving the cutting blades through a cutting cycle, the other drive mechanism may be simultaneously reset. Thus, this alternate arrangement offers the further advantage of an even shorter overall recycling time, with the result that even shorter scrap lengths may be produced by successive cuts.

It will be appreciated that various modifications may be made to the above-described embodiments without departing from the spirit and scope of the invention. By way of example, other forms of one way clutch assemblies may be employed. Also, the design of the drive mechanism may vary, as by employing only one gear rack with the pinion gear keyed to shaft extension 34. This modification may be in order where torque requirements are lower, as when smaller cross sections are being cut.

In light of the foregoing, it will now be apparent that use of this invention is not limited to rolling mill applications. The invention may be employed to cut all types of moving elongated elements by using appropriate cutting blades and by selecting suitable gear ratios for the various racks and pinions to achieve the proper cutting speeds.

It is my intention to cover all changes and modifications to the embodiments herein chosen for purposes of disclosure which do not constitute departures from the spirit and scope of the invention.

lclaim:

1. Apparatus for cutting a moving elongated element comprising: a housing supporting a pair of spaced rotatable shafts; gear means for mechanically interconnecting said shafts in a manner such that rotation of one shaft in one direction imparts a corresponding rotation to the other shaft in the opposite direction; cutting blades carried by each of said shafts, said cutting blades cooperating during rotation of said shafts in opposite directions to cut an elongated element moving therebetween; and operating means connected to at least one of said shafts for rotation said shafts to achieve the aforesaid cutting action, said operating means including a reciprocally operating drive mechanism acting through a one-way clutch assembly to intermittently rotate the said one shaft in one direction only.

2. The apparatus as claimed in claim ll wherein said clutch assembly is comprised of a first clutch element connected to the said one shaft for rotation therewith, a second clutch element connected to a third shaft for rotation therewith, and means for interconnecting said clutch elements in a manner such that rotation of said third shaft and said second clutch element in one direction will impart corresponding rotation to said first clutch element and said one shaft in the same direction, while rotation of said third shaft and said second clutch element in the opposite direction will not impart corresponding rotation to said first clutch element and the said one shaft connected thereto.

3. The apparatus as claimed in claim 2 wherein said drive mechanism is comprised of a pinion gear connected to said third shaft for rotation therewith, at least one gear rack extendin in a direction transverse to the rotational axispf said third 5 aft, sard gear rack being in meshed relationship with said pinion gear, and power means for reciprocally actuating said gear rack to produce rotation of said pinion gear and third shaft first in one direction and then in the opposite direction.

4. The apparatus as claimed in claim 3 wherein said power means is comprised of a piston at either end of said gear rack, each said pistons being reciprocally contained within cylinder chambers, and means for alternately feeding hydraulic fluid into one of said chambers while simultaneously bleeding hydraulic fluid from the other of said chambers.

5. The apparatus as claimed in claim 1 wherein operating means are connected to each of said shafts.

6. Apparatus for cutting a moving product length comprising: a stationary housing, a pair of spaced parallel shafts rotatably supported by said housing, gear means for interconnecting said shafts in a manner such that rotation of one shaft in one direction produces simultaneous rotation of the other shaft in the other direction, cutting blades carried by each said shafts, the said blades being positioned to shear a product length passing therebetween when said shafts are rotated in opposite directions, clutch means having a drive element connected to one of said shafts and a driven element connected to a third shaft, whereupon rotation of said third shaft in one direction will produce rotation of said one shaft in the same direction, while rotation of said third shaft in the opposite direction will result in no corresponding rotation being imparted to said one shaft, a pinion gear mounted on said third shaft, at least one gear rack in meshed relationship with said pinion gear, said gear rack being mounted for reciprocal motion in a direction transverse to the rotational axis of said third shaft, and means for reciprocating said gear rack.

7. Apparatus for cutting a moving product length comprising: a stationary housing, a pair of spaced parallel shafts rotatably supported by said housing, gear means for interconnection said shafts in a manner such that rotation of one shaft in one direction produces simultaneous rotation of the other shaft in the opposite direction, cutting blades carried by each said shafts, the said blades cooperating to cut a product length passing therebetween when said shafts are rotated, and operating means for rotating one of said shafts in one direction, said operating means including a reciprocating drive mechanism acting through a one-way clutch assembly.

. UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 r 677 r Dated J ly 18 1972 Inventor(s) Donald rln It is certified that error appears in the above-identified patent and that: said Letters Patent are hereby corrected as shown below:

Col. 1, lines 48 and 49, delete "a View in front end elevation" and insert therefor an end view--; v

Col. 2, line 26, delete "wheel" and'insert therefor --"free wheel"-;

Col. 2, line 28, delete "The" and insert Referring now to Figure 3, it will be seen that the--;

Col. 3, line 4, after "area" delete "a" and insert of approximately-;

Col. 3, line 5, after "hour" insert a period Col. 3, line 5, before "travels" insert At this production rate, the cast section-- Signed and sealed this 17th day of April 1973.

Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestlng Officer Commissioner of Patents FORM po'wso (1069) USCOMM-DC 60376-P69 i U.5. GOVERNMENT PRINTING OFFICE: I969 0-366-334 

1. Apparatus for cutting a moving elongated element comprising: a housing supporting a pair of spaced rotatable shafts; gear means for mechanically interconnecting said shafts in a manner such that rotation of one shaft in one Direction imparts a corresponding rotation to the other shaft in the opposite direction; cutting blades carried by each of said shafts, said cutting blades cooperating during rotation of said shafts in opposite directions to cut an elongated element moving therebetween; and operating means connected to at least one of said shafts for rotation said shafts to achieve the aforesaid cutting action, said operating means including a reciprocally operating drive mechanism acting through a one-way clutch assembly to intermittently rotate the said one shaft in one direction only.
 2. The apparatus as claimed in claim 1 wherein said clutch assembly is comprised of a first clutch element connected to the said one shaft for rotation therewith, a second clutch element connected to a third shaft for rotation therewith, and means for interconnecting said clutch elements in a manner such that rotation of said third shaft and said second clutch element in one direction will impart corresponding rotation to said first clutch element and said one shaft in the same direction, while rotation of said third shaft and said second clutch element in the opposite direction will not impart corresponding rotation to said first clutch element and the said one shaft connected thereto.
 3. The apparatus as claimed in claim 2 wherein said drive mechanism is comprised of a pinion gear connected to said third shaft for rotation therewith, at least one gear rack extending in a direction transverse to the rotational axis of said third shaft, said gear rack being in meshed relationship with said pinion gear, and power means for reciprocally actuating said gear rack to produce rotation of said pinion gear and third shaft first in one direction and then in the opposite direction.
 4. The apparatus as claimed in claim 3 wherein said power means is comprised of a piston at either end of said gear rack, each said pistons being reciprocally contained within cylinder chambers, and means for alternately feeding hydraulic fluid into one of said chambers while simultaneously bleeding hydraulic fluid from the other of said chambers.
 5. The apparatus as claimed in claim 1 wherein operating means are connected to each of said shafts.
 6. Apparatus for cutting a moving product length comprising: a stationary housing, a pair of spaced parallel shafts rotatably supported by said housing, gear means for interconnecting said shafts in a manner such that rotation of one shaft in one direction produces simultaneous rotation of the other shaft in the other direction, cutting blades carried by each said shafts, the said blades being positioned to shear a product length passing therebetween when said shafts are rotated in opposite directions, clutch means having a drive element connected to one of said shafts and a driven element connected to a third shaft, whereupon rotation of said third shaft in one direction will produce rotation of said one shaft in the same direction, while rotation of said third shaft in the opposite direction will result in no corresponding rotation being imparted to said one shaft, a pinion gear mounted on said third shaft, at least one gear rack in meshed relationship with said pinion gear, said gear rack being mounted for reciprocal motion in a direction transverse to the rotational axis of said third shaft, and means for reciprocating said gear rack.
 7. Apparatus for cutting a moving product length comprising: a stationary housing, a pair of spaced parallel shafts rotatably supported by said housing, gear means for interconnection said shafts in a manner such that rotation of one shaft in one direction produces simultaneous rotation of the other shaft in the opposite direction, cutting blades carried by each said shafts, the said blades cooperating to cut a product length passing therebetween when said shafts are rotated, and operating means for rotating one of said shafts in one direction, said operating means including a reciprocating drive mechanism acting through a one-way clutch assembly. 